I have a tank right now with no fish in it but a bunch of live rock with a lot of aptasia. I bought 3 peppermints to put them in and 2 of them disappeared, one of them died. I am not seeing any of the aptasia dead and it's been about 4 days or so and still havent seen the other peppermint shrimps.. I am assuming they died as well. The tank is very young but there isnt any bioload in there but there is all liverock and livesand. I have a turbo snail and a couple of hermit crabs in there and they seem to be doing fine, this is a half filled 72 gallon BTW.
I am leaving it half filled till I get a new trim for the top since my center brace broke.